When you say snow removal, exactly what do you envision? Using the FEL or a blade to push stuff around? Getting a 3pt snow blower? Or going with a front mount option? From your posts I assume that when you say "forestry maintenance" you are talking about removing trees (though I read something about skidding). Finally when you say road maintenance are you talking about maintaining your road or building new roads?
Either tractor will work just fine for what I think you are going to use it for. Those who say the GL is a rich man's toys should be ignored. It's a tool that will last just as long as the M will. Extra weight isn't always nice. If you have areas that get muddy that weight will work against you. I'm assuming you have a long driveway (since you have 47 acres) and being in the hills it's most likely not straight. To me that screams front mount snow blower. If so the the GL wins hands down. It has a mid PTO option for a front blower and the HST+ can't be beat for snow blowing. Set your engine speed with a geared/ shuttle tractor and you've also set your speed. When you come up on a drift you have change gears. With an HST you can just slow down. With the HST+ you can shift down for parts where you really need to slow down without even letting off the treddle.
I have both shuttle and hst and the only reason I use the shuttle is because the loader is almost twice the size. I find it annoying as you have to rev the motor up to get the hydraulics to speed up but when you do you either have to shift into neutral or hold the brake. Often I creep forward some then stop as I curl the loader. My Case has a button on the FEL control to shift into neutral but when you release it and the motor is revving high it's kind of abrupt. With the HST+ I can shift down just as I'm about to start to dig into a pile of dirt and then shift back up as I'm reversing away. With shuttle I'm always finding that the gear I'm in isn't quite right and always seam to shift or just try to work with it.
I don't see anything you propose pushing the HP you are talking about to the point where loosing a couple is going to be a deal breaker. I have nothing against the M6060, bet it's a fine tractor. But in my personal opinion you are looking for a compromise to do multiple tasks. That really means HST is more likely to work better for you.